Ignition coils are known for use in connection with an internal combustion engine such as an automobile engine. Ignition coils typically include a primary winding, a secondary winding, and a magnetic circuit. The magnetic circuit conventionally may include a central core extending along an axis and located radially inward of the primary and secondary windings and magnetically coupled thereto. The components are contained within a case formed of an electrical insulating material with an outer core or shield located outside of the case. One end of the secondary winding is conventionally configured to produce a relatively high voltage when a primary current through the primary winding is interrupted. In a common configuration, insulating resin or the like is introduced into the gap between the secondary winding and the case for insulating purposes. A high voltage cup in electrical communication with the high voltage end of the secondary winding may be press fit within the casing to facilitate coupling with a spark plug that is arranged to generate a discharge spark responsive to the high voltage. However, the area of press fit between high voltage cup and the case may be prone to a void in which an electrical field may concentrate.
What is needed is an ignition coil which minimizes or eliminates one or more of the shortcomings as set forth above.